/*!	 timeloop.cpp
**	 Implementation of the "Time Loop" layer
**
**	Copyright (c) 2002-2005 Robert B. Quattlebaum Jr., Adrian Bentley
**	Copyright (c) 2007, 2008 Chris Moore
**	Copyright (c) 2011-2013 Carlos López
**
**	This package is free software; you can redistribute it and/or
**	modify it under the terms of the GNU General Public License as
**	published by the Free Software Foundation; either version 2 of
**	the License, or (at your option) any later version.
**
**	This package is distributed in the hope that it will be useful,
**	but WITHOUT ANY WARRANTY; without even the implied warranty of
**	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
**	General Public License for more details.
**
** === N O T E S ===========================================================
**
** ========================================================================= */

#ifdef USING_PCH
#	include "pch.h"
#else
#ifdef HAVE_CONFIG_H
#	include <config.h>
#endif

#include <synfig/localization.h>
#include <synfig/general.h>

#include "timeloop.h"
#include <synfig/valuenode.h>
#include <synfig/valuenodes/valuenode_const.h>
#include <synfig/valuenodes/valuenode_subtract.h>
#include <synfig/time.h>
#include <synfig/context.h>
#include <synfig/paramdesc.h>
#include <synfig/renddesc.h>
#include <synfig/value.h>
#include <synfig/canvas.h>

#endif

using namespace std;
using namespace etl;
using namespace synfig;
using namespace modules;
using namespace lyr_std;

SYNFIG_LAYER_INIT(Layer_TimeLoop);
SYNFIG_LAYER_SET_NAME(Layer_TimeLoop, "timeloop");
SYNFIG_LAYER_SET_LOCAL_NAME(Layer_TimeLoop, N_("Time Loop"));
SYNFIG_LAYER_SET_CATEGORY(Layer_TimeLoop, N_("Time"));
SYNFIG_LAYER_SET_VERSION(Layer_TimeLoop, "0.2");
SYNFIG_LAYER_SET_CVS_ID(Layer_TimeLoop, "$Id$");

Layer_TimeLoop::Layer_TimeLoop()
{
    old_version = false;
    param_only_for_positive_duration = ValueBase(false);
    param_symmetrical = ValueBase(true);
    param_link_time = ValueBase(Time(0));
    param_local_time = ValueBase(Time(0));
    param_duration = ValueBase(Time(1));

    SET_INTERPOLATION_DEFAULTS();
    SET_STATIC_DEFAULTS();
}

Layer_TimeLoop::~Layer_TimeLoop()
{
}

bool
Layer_TimeLoop::set_param(const String & param, const ValueBase &value)
{
    if (old_version) {
        if (param == "start_time" && value.same_type_as(start_time)) {
            value.put(&start_time);
            return true;
        }

        if (param == "end_time" && value.same_type_as(end_time)) {
            value.put(&end_time);
            return true;
        }
    } else {
        IMPORT_VALUE(param_local_time);
        IMPORT_VALUE(param_link_time);
        IMPORT_VALUE(param_duration);
        IMPORT_VALUE(param_only_for_positive_duration);
        IMPORT_VALUE(param_symmetrical);
    }

    return Layer::set_param(param, value);
}

ValueBase
Layer_TimeLoop::get_param(const String & param)const
{
    EXPORT_VALUE(param_link_time);
    EXPORT_VALUE(param_local_time);
    EXPORT_VALUE(param_duration);
    EXPORT_VALUE(param_only_for_positive_duration);
    EXPORT_VALUE(param_symmetrical);
    EXPORT_NAME();
    EXPORT_VERSION();

    return Layer::get_param(param);
}

Layer::Vocab
Layer_TimeLoop::get_param_vocab()const
{
    Layer::Vocab ret(Layer::get_param_vocab());

    ret.push_back(ParamDesc("link_time")
                  .set_local_name(_("Link Time"))
                  .set_description(_("Start time of the loop for the cycled context"))
                  .set_static(true)
                 );

    ret.push_back(ParamDesc("local_time")
                  .set_local_name(_("Local Time"))
                  .set_description(_("The time when the resulted loop starts"))
                  .set_static(true)
                 );

    ret.push_back(ParamDesc("duration")
                  .set_local_name(_("Duration"))
                  .set_description(_("Lenght of the loop"))
                  .set_static(true)
                 );

    ret.push_back(ParamDesc("only_for_positive_duration")
                  .set_local_name(_("Only For Positive Duration"))
                  .set_description(_("When checked will loop only positive durations"))
                  .set_static(true)
                 );

    ret.push_back(ParamDesc("symmetrical")
                  .set_local_name(_("Symmetrical"))
                  .set_description(_("When checked, loops are mirrored centered at Local Time"))
                  .set_static(true)
                 );

    return ret;
}

bool
Layer_TimeLoop::set_version(const String &ver)
{
    if (ver == "0.1") {
        old_version = true;
    }

    return true;
}

void
Layer_TimeLoop::reset_version()
{
    Time link_time, local_time, duration;
    bool only_for_positive_duration, symmetrical;

    // if we're not converting from an old version of the layer, there's nothing to do
    if (!old_version) {
        return;
    }

    old_version = false;

    // these are the conversions to go from 0.1 to 0.2:
    //
    //	 local_time = start_time
    //	 duration = end_time - start_time
    //	   link_time = -duration : if we want to reproduce the old behaviour - do we?
    //	 else
    //		 link_time = 0

    // convert the static parameters
    local_time = start_time;
    duration = end_time - start_time;
    only_for_positive_duration = true;
    symmetrical = false;

    param_local_time.set(local_time);
    param_duration.set(duration);
    param_only_for_positive_duration.set(only_for_positive_duration);
    param_symmetrical.set(symmetrical);

    // TODO:  layer version 0.1 acted differently before start_time was reached - possibly due to a bug
    link_time = 0;
    param_link_time.set(link_time);

    // convert the dynamic parameters
    const DynamicParamList &dpl = dynamic_param_list();

    // if neither start_time nor end_time are dynamic, there's nothing more to do
    if (dpl.count("start_time") == 0 && dpl.count("end_time") == 0) {
        return;
    }

    etl::rhandle<ValueNode> start_time_value_node, end_time_value_node;
    LinkableValueNode* duration_value_node;

    if (dpl.count("start_time")) {
        start_time_value_node = dpl.find("start_time")->second;
        disconnect_dynamic_param("start_time");
    } else {
        start_time_value_node = ValueNode_Const::create(start_time);
    }

    if (dpl.count("end_time")) {
        end_time_value_node = dpl.find("end_time")->second;
        disconnect_dynamic_param("end_time");
    } else {
        end_time_value_node = ValueNode_Const::create(end_time);
    }

    duration_value_node = ValueNode_Subtract::create(Time(0));
    duration_value_node->set_link("lhs", end_time_value_node);
    duration_value_node->set_link("rhs", start_time_value_node);

    connect_dynamic_param("local_time", start_time_value_node);
    connect_dynamic_param("duration",   duration_value_node);
}

void
Layer_TimeLoop::set_time_vfunc(IndependentContext context, Time t)const
{
    Time link_time = param_link_time.get(Time());
    Time local_time = param_local_time.get(Time());
    Time duration = param_duration.get(Time());
    bool only_for_positive_duration = param_only_for_positive_duration.get(bool());
    bool symmetrical = param_symmetrical.get(bool());

    Time time = t;
    float document_fps = get_canvas()->rend_desc().get_frame_rate();

    if (!only_for_positive_duration || duration > 0) {
        if (duration == 0) {
            t = link_time;
        } else {
            float t_frames = round(t * document_fps);
            float duration_frames = round(duration * document_fps);

            if (duration > 0) {
                t -= local_time;
                // Simple formula looks like this:
                // but we should make all calculations in frames to avoid round errors
                t_frames -= floor(t_frames / duration_frames) * duration_frames;
                // converting back to seconds:
                t = t_frames / document_fps;
                t = link_time + t;
            } else {
                t -= local_time;
                // Simple formula looks like this:
                // but we should make all calculations in frames to avoid round errors
                t_frames -= floor(t_frames / -duration_frames) * -duration_frames;
                // converting back to seconds:
                t = t_frames / document_fps;
                t = link_time - t;
            }
        }

        // for compatibility with v0.1 layers; before local_time is reached, take a step back
        if (!symmetrical && time < local_time) {
            t -= duration;
        }
    }

    context.set_time(t);
}